Figure 2.

Total number of isolated individuals as a function of time, according to (9), in the four cases, from left to right: $\kappa =0$, κ as in (20), 10κ and 20κ. Remarkably, in the latter case the peak of the map $t\to \iint H\mathrm{d}a\mathrm{d}x$ is lower than on the preceding case. Indeed, a high value of κ reduces the number of infectives and, as a consequence, may also reduce the total number of individuals in quarantine